Answer:
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Soot is formed as a candle burns
a
Chemical Change
b
Physical Change
Answer:
Chemical change
Explanation:
Because a new substance is formed.
9
23 What is a use of sulfuric acid?
A
as a bleach
B.
as a food preservative
in the manufacture of detergents
D.
in the manufacture of
vanadium(V) oxide, V205
Answer:
B. as a food preservative in the manufacture of detergents
.........
Explain the four basic types of chemical reactions. Be sure to include a sample equation for each type. Describe how rate relationships and activation energy are important in chemical reactions.
Answer:
Synthesis reaction is 2 or more chemical combing to form complex product (A+B→AB)
Decomposition occurs when one reactant breaks down into 2 or more products (H2CO3→H2O+CO2)
Single replacement is a reaction when one element is substituted for another element compound. (A+BC→ AC+B)
Double replacement occur when parts of 2 ionic compounds are exchanged making two new compounds .(A+B - + C + D- → A+D- +C )
The activation energy of the particular reaction will determines the rate at which it will go. The higher the activation energy gets, the slower the chemical reaction will become.
Explanation:
You want to test the effect of soil acidity on plant growth. Which of the
following is an example of a controlled experiment to test this?
A. The plant type, amount of light, and amount of water are kept
constant while soil acidity is varied for plants in a greenhouse.
B. The soil acidity of plants in a garden that get light and water from
their surroundings is increased after the plants grow to a height of
100 cm.
C. The plant type, soil acidity, amount of light, and amount of water
are all varied and studied in a laboratory.
D. Soil acidity and height of plants growing in a 10 m2 yard are
measured twice in July and twice in August.
Answer:
I believe the answer to your question would be A. this is because it is controlled with a good habitat and also has good variants that are needed in a good plants growth.
Explanation:
Dissolving salt in water is what kind of reaction
O Endothermic reaction
O Exothermic reaction
O No answer text provided
O No answer text provided
Answer:
endothermic reaction
Explanation:
because salt dissolve water
Answer:
EXOTHERMIC REACTION AS WHEN YOU TOUCH IT YOU WILL FEEL SOME HEAT.
What is the equation to calculate the volume of a cylinder?
O V = (77/4)*72 +h
O V=1* w* h
O V = (4/3)*r
O V = m*d2
Answer:
the equation for cylinders is V = (pi)r2h
none of these are even close but i can do a little more research
sorry if this one wasnt as much help
Balance the following chemical equation and explain how u got it
a. Fe + O2 →Fe2O3
b. FeBr3 + H2SO4 → Fe2(SO4)3 + HBr
c. C4H6O3 + H2O → C2H4O2
Explanation:
just trying...hope that helps
Which result would support the particle theory of light? Increasing the intensity of the light causes electrons to be ejected. Frequencies of light that fall below the frequency threshold of the metal do not eject electrons. There is a time gap between when light strikes the metal and when electrons are ejected.
Frequencies of light that fall below the frequency threshold if the metal do not eject electrons.
what dose gravity measure ?
Answer:
the acceleration that it gives to freely falling objects.
Explanation:
i took quiz
Why do scientists use models of molecules?
A. To research the known effects of the molecule on the environment
B. To explain how electrons, protons, and neutrons are arranged
C. To show the structure of molecules, which are too small to see
D. To design an experimental setup to synthesize molecules
Answer:
C
Explanation:
What is astronomy? Why is the study of astronomy important to humans?
Answer and Explanation:: Astronomy is the study space and what it contains. Astronomy should be studied by mankind because our survival is directly linked to the cosmos. The Earth is heated by its nearest star, the Sun, and its ocean tides are directly connected to its only satellite, the Moon.
Answer:
Astronomy is the study of stars and planets. It is important to humans because it helps us know if there is a supernova close to earth and more imformation about stars and planets that we need to know.
Problem Page Question A major component of gasoline is octane C8H18. When liquid octane is burned in air it reacts with oxygen O2 gas to produce carbon dioxide gas and water vapor. Calculate the moles of octane needed to produce 2.4mol of water. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits. 2.4 Clears your work. Undoes your last action. Provides information about entering answers.
Answer:
0.3mol C8H18
Explanation:
For this we must first look at the reaction taking place:
C8H18+O2 --> H2O + CO2
Balancing the equation we get:
2(C8H18)+25(O2) --> 18(H2O) + 16(CO2)
Form there we now need to know how many moles of Octane are needed to produce 2.4moles of H2O. The conversion is as follows:
2.4molH2O ((2mol of C8H18)/(18mol of H2O)) = 0.3mol C8H18
Do experiments always turn out as
expected? Why or why not?
Answer:
no
Explanation:
When doing experiments, it's to find out how what you're doing will end up in the results. Even when expecting something, it may not end up that way. Trial and Error you could say
A photon of 498nm was emmited from a silicon atom. Calculate the energy of all the atomic levels of silicon and show that The atomic levels are quantized
Answer:
3.99 × 10 ^-28
Explanation:
In the equation of E = hc/λ, the h = 6.626 × 10^−34 J and c = 3 × 10^8 m/s
E = 6.626 × 10^−34 × 3 × 10^8 divided by 498
E = 3.99 × 10 ^-28
(b) Liquids and gases flow because…?
The molecules of gases and liquids are present far apart from each other. In other words, they have more gaps or intermolecular spaces. Due to the large intermolecular forces, the intermolecular attractions are very less and thus liquids and gases can flow.
A block of aluminium occupies a volume of 15.ml and weighs 40.5 g. What is its density? 2700kg /m3
Answer: d = 2.70 g/mL
Explanation: Considering we know that it weights 40.5 brains and the volume of such amount is 15 ml we can calculate such in which it comes to be 2.7 grams per mL
I need help on this, It’s due today. Please, anybody
Answer:
1 = 252g, 2 = 2mL, 3 = 1.5mL, 4 = 3g, 5 = 225g, 6 = 0.92g/mL, 7 = 0.75g/mL, 8 = 0.71g/mL, 9 = 1.9mL, 10= 1.11mL, 11 = 76.9g
Explanation:
This problem is testing how well you can move around the equation D = m/v where D = Density (g/mL), m= mass of sample (g), v = volume of sample (mL).
If an object has a mass of 43.23 g and a volume of 32.1 mL, what is its density? Show your work!
Answer: 1.34 g/ml
Explanation: Density is an objectives mass divided by it's volume:
(43.23 g)/(32.1 ml) =1.34 g/ml
La temperatura más baja registrada en EEUU fue de - 70 °F (en Roger Pass montana). Exprese esta temperatura en °C
(Porfavor ayudenme)
Answer:
[tex]thank \: yo[/tex]
Convert 6.5 cm3 to m3
the Answer is
6.5e-6 m^3
[6.5e-6 = 6.5 x 10-6 = 0.0000065]
Answer:
0.0000065 m³
Explanation:
To convert a cubic centimeter measurement to a cubic meter measurement, divide the volume by the conversion ratio.
Since one cubic meter is equal to 1,000,000 cubic centimeters, you can use this simple formula to convert:
cubic meters = cubic centimeters ÷ 1,000,000
m³ = 6.5 ÷ 1,000,000
m³ = 0.0000065
Explain why nitrogen is a gas at room temperature.
Answer in terms of nitrogen's structure.
Nitrogen exists as a diatomic molecule, N2 (subscript 2). It exists as a gas at room temperature because of the type of interactions with other identical molecules: weak intermolecular forces are present between the molecules, specifically temporary dipole-dipole interactions.
These interactions are the second weakest type of intermolecular force (Van Der Waals and Hydrogen Bonds are the other two with Hydrogen Bonds being stronger).
Now the reason why Nitrogen exists as gas is that these weak intermolecular forces can be overcome with little energy. Therefore, at room temperature, Nitrogen exists as a gas.
What is nitrogen gas at room temperature?Nitrogen has a low melting and boiling point and is a gas at room temperature. The Earth's atmosphere is made up of 78% nitrogen. The next most common gas is oxygen, at 21%. Nitrogen isn't very reactive, but it can react with oxygen at high temperatures, such as in-car engines.
What is the nitrogen structure?Nitrogen forms an extensive series of nitrides with carbon, including those with chain-, graphitic-, and fullerene-like structures.
Learn more about What is nitrogen gas at room temperature? here: https://brainly.com/question/14747312
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A 1-L soda bottle contains dissolved carbon dioxide gas. Which bottle would have the highest concentration of dissolved gas?
a bottle that is sealed
a bottle that was opened 1 minute ago
a bottle that was opened 1 hour ago
a bottle that was opened 1 day ago
Mark this and return
Answer:
A bottle that is sealed would have the highest concentration.
Explanation:
When you put a gas into a container, the concentration or the amount of mol inside the bottle would be highly concentrated. If you open the bottle, the CO2 would spread outwards and leave the bottle giving more room between each molecule. The longer you open the bottle, the less concentrated the gas will be.
Suppose it takes 21 min for 2.4 g of sugar to completely react with another reagent we added to the flask. What would the reaction rate be
Define density, and list two reasons it is important in science
Answer:
The density is the mass per unit volume of a substance.
Density is important when working out if something will float in water, and it can also be useful for calculating the mass of a specific volume of a substance.
Explanation:
what is true about chemicals?
A. Chemicals are rarely found on earth
B. Chemicals are never dangerous
C. Chemicals are in many substances in a home
D. Things containing chemicals always cost a lot of money
hi <3
i believe the correct option would be C
hope this helps :)
Could someone plz help me? :(
Answer:
eu sou do brasil :D gostaria de saber como é ai nos estados unidos :D
Explanation:
Answer:
Explanation:
I think that C is the best limitation you could pick. I doubt you could be on the beach at 4 am. So the gulls that visit the beach would be unknown to you at night. That's half the day you could not account for.
True or false: animals use photosynthesis to make food
9 The relative abundances of the two isotopes of chlorine are shown in this table:
Relative abundance
Isotope
35C1
75%
3701
25%
Use this information to deduce the mass spectrum of chlorine gas
Answer:
35.50 atomic mass
Explanation:
1. Multiplicate each isotope mass by its abundance
35 uma x 75% = 26.25 amu
37.01 uma x 25% = 9.2525 amu
2. Add the values
26.25 + 9.2525 = 35.50 atomic mass
In a titration, when the number of moles of hydrogen ions equals the number of moles of hydroxide ions, what is said to have happened?
The equivalence point has been reached.
The point of neutralization has been reached.
The end point has been reached.
An explanation for a broad of observation, facts, and tested hypothses is called a
Answer:
that's is a theory
Explanation:
hope it may help you